I would do role play with the children, with a dog cuddly toy. Spend this week role playing with them how the puppy is likely to behave, and how they should handle it - for example when the puppy is jumping up and getting overexcited, they should stay calm and turn their backs and know you will come and help, rather than running away or screaming. Role play putting your puppy in the crate and stress that there is to be no contact with pup when they're in there. Role play training techniques so they know the right words and signs to use for each 'trick' - this way you can all be consistent.
I would strongly advise you have boundaries about where the dog can go in the house, and stick to them. If pup is confined to the kitchen and garden for example, you won't have to worry about them chewing up toys because you can have a blanket rule of 'no toys in the kitchen', which again you should implement now. I would discourage you from allowing pup on furniture at all. As long as they have a lovely comfy bed there's no need, and it'll be good long term for keeping things clean and hygienic, and always mean the kids can get on the sofa or whatever to have a rest from pup - they will find the dog overwhelming and exhausting at times.
Have a think now where your children will be when you need to be alone in the kitchen or garden with the puppy - are they safe to wander around the rest of the house? Do you perhaps need to re-look at your playroom to be sure it's the safest it can be for leaving your little one in there alone - cupboards attached to walls, toys with tiny chokeable pieces stored away, electrical outlets hidden, wall mounted TV rather than freestanding, pens, scissors and craft materials put away somewhere inaccessible. Let's say your pup has horrible diarrhoea one day and you need a good 20 minutes to get everything sorted without your kids 'helping' (I've been there!!) you need to know you can put them in the playroom/living room/wherever and that they're safe while you're tackling the disaster zone.
Re walking, I know you're keen to enjoy long walks when your dog is grown, but during the first year or 2 while they are growing you need to limit walks so as not to risk damage to growth plates. Not to say they shouldn't have walks, but just hold off with the serious hikes! Look at snuffle mats, kongs, Nina Ottoson dog toys etc to use up mental energy instead, and of course do lots of training. Good luck!